Exhaust muffler



' 7 1927 w. F. BOUCHE ET AL EXHAUST MUFFLER Filed Feb. 16, 1922 gvwomtozi Buns/J Patented June 14, 19. .7a

status aaraa WILLIAM BOUGHE, or naivoasrna, Ann nnia. nnann, or nonrano, new roman, assreivons. BY Mnsnn assreuarnn'rs, 'ro south can LIGHTING-EORPORATIOIN, or nocnns'rnn, new "roan, a coaronnrrouonraanrnaun.

nxrmusr MUFFLER. I I

Application filed meat The invention relates to improvements in exhaust mufflers which are particularly adapted for use in connection with steam turbines, or the like. In steam turbines the steam leaves the turbine buckets in a successiouof puffs succeeding one another at the frequency at which the buckets pass agiven point. This frequency may be within the range of audible frequencies and in consequence an objectionable shrill noise may be caused which issues largely from the exhaust pipe.

The presentinvention is designed to provide an improved form of exhaust muffler which may be used in connection with a device from which steam or other gas would otherwise issue at such frequencies as to produce audible sounds, the muffler operating in such a manner as to cause the exhaustto issue therefrom practically without sound; .This may be accomplished in accordance with the preferredform of the invention by the provision of means whereby the issuing steam or the gas is caused. to travel through a plurality of circuitous paths of different lengths, on their way to the exit opening of the muffler.

Another object of the invention is the provision of an improved turbine structure in which anexhaust muffler is incorporated in the casing or in the cover plate of the turbine. Other objects and advantages of the invention will appear more fully hereinafter in the following specification.

' In order that a clearer understanding of the invention may be hadattention is hereby directed to the accompanying drawings forming part of this application and illuse0 drawings Fig. 1 represents avertical section taken through a steam turbine of the general type described in Letters Patent No. 94 11 839; No. 1,042,87L and No. 1, %,465, and having a casing with an exhaust muffler secured thereto to constitute a covering means there-' for, and Fig. 2 1s a vertical sectlon taken on line 22 of Fig. 1.

Referring to the drawings, the turbine trating one embodiment thereof. ln the 16, 19a. Serial uni 536,900.

bucket wheel 1 is mounted on the over-hang- .ing end. of a shaft 2 which is illustrated as supported. within a ball bearing .3 within a housing member 4rattached to a machine which may be driven by the turbine. a portion of'which is indicated at 5 andwhic-h maybe an electric generator or other device. A casting 6 attached to the housing plate t is so formed as to serve as an enclosing member for the oil chamber 6 surrounding bearing 3, casting 6 also serving as a casing 6 member for the tiirbine bucket wheel 1.

Attached to a flat face on the top of the casing member 6 is a nozzle and bucket guide member 7. Steam or other. gas is supplied to the nozzle by a pipe 9 connected to the nozzle member 7 by the connection 8.

The outward end of the turbine case 6 is closed by a cover plate 10 secured to casing member 6 by suitable means such as the cap screws 11.- A muffler cap 12 is secured by suitable means such as the cap screws 13 to the coverplate 10.

Members 10 and 12 together form a muffler casing. which is preferably of annular box like form as shown. The exhaust from the "turbine issues past the end of shaft 2 into a space l l-which preferably surrounds the axis of the muffler casing and is in alignment with shaft 2, from which space the exhaust steam or other gas passes to the exhaust opening 15 of the muffler.

The muffler is so constructed as to provide a plurality of ribs about whichthe ex- ,haust will have to pass on its way to the outlet 15. Preferably these ribs, 16, 17 and 35 -18 are formed partly on cover plate 10 and partly on cap member 12. As is shown in Fig. l'members 10 and 12, each have a portion of the ribs referred to directed towards the. other, the aligned portions of these ribs engaging along the plane indicated at 19, the adjacent faces of the contacting members being finished flat to provide an easily manufactured joint.

The annular rib 16 thus formed extends across-the muffler casing from one side to the other, surrounding space 14 into which the exhaust steam from the turbine wheel enters.

of alignment with openings. 22 in rib 17..

The annular space 25, which is surrounded by casing member 12: leads the steam intouthe exhaust opening 15,- which is shown as threaded toreceive an exhaust pipe.

1 It will be noted that the turbinecase with the-cover plate and muffler cap completely enclose the turbine wheel. The-.space enclosed. within the (turbine case and cover plate communicates with the atmosphere only by the indirect paths leading from space l t to exhaust opening. 15,. indicated. by the arrows in the drawings. These paths also constitute the only channels through'avhich sound waves inay travel from the lnterlor of 'the turbine casing. to the discharge. end oftthe exhaustpipe.

It will be observed that the paths through which the gases pass to the discharge opening are repeatedly reversed. in direction. It will also be noted that a plurality of paths are provided betweentheentrance and exhaust openingsof the muiiler which are of different lengths each from the other.

Thus some of the exhaust-will. proceed upwardly through the openings in ribs 16 17 and 18 by a comparatively short: path. while another portion .ofqthe exhaust will pass through the lowermost opening in rib'16 and. will have a longer; path totravel tothe discharge opening 15. In the passage from each annular space to the next annular space the exhaust will divide and pass through different openings so that at each reversal of direction of the exhaust steam. or other gas the latter will divide between paths of different lengths. Accordingly the wave impulses passing-through the muffler will be outof step with each other as they enter the exhaust opening 15 and will interfere so as to prevent the exhaust from leaving the opening 15 in a manner to-setup sound waves in the outside atmosphere.

In the preferred form of device,-as illustrated, a pluralityof annular passages SET-0 roundingeach other are providechin eachv of which a portion of the sound propagat-i jing impulses are eliminated so that the impulses which would propagate sound are successively diminished from one stage to the other in what maybe .a geometricprogression with the final result of nearly silent running so far as concerns the noise which would otherwise be produced as the steam leaves the turbine buckets.

It may also be noted that sound suffers diminutionwhen its course of travelis obstructed and that our construction provides an enclosure in which the sound waves are caused to pass through labyrinth-like passages in which the direction of" travel is repeatedly reversed.

"It should be inoted that the invention is not limited strictly to the details of construction described but is as broad as is indicated .by the accompanying claims.

hat we claim is 1...In.an.apparatus of the class described thercombination of'a turbine having av casing surrounding the turbine wheel thereof, and anexhaust muffler rigid with the casing and forming an extension of the casing,

.part of the turbine wheel casing forming part of the. mufiier,.- and said. mufller havlng .baffling means rigid withsaid casing causingltheexhaustgases to pass 1n a general radial. direction through themufiler.

2. In an apparatus of the class-described the combination of a turbine wheel, a casing member, a cover plate therefor and muffler .cap member all rigidly secured with respect to one-another and with the first two members. substantially enclosing the turbine wheel, and muffiing means carried rigid with and. between the last two mentioned members.v V

. 3. Apparatus of the class described comprising a turbine and its casing, having. an exhaust outlet substantially at the turbine axis and amufiierrigidly secured with respect tothe turbine casing and having its inlet connected withsaid exhaust outlet and also. substantially. at the turbine axis.

4. In an apparatus of the class described the combination of aturbine, said turbine having a casing providing a relatively flat- .t-hin chamber for. the turbine wheel, and a relatively fiat thin mufiling chamber situated adjacent thereto and rigid therewith,

the general planev of said chambers being substantially parallel and said chambers being connected for the passage of exhaust steam from one to the other. substantially at'the turbine axis.

L 5; Inanapparatusofthe class described, the combination of a turbine having. astationary casing for the turbine wheel, .a cover plate. member rigidly but removably secured to the casing, and a stationary muftler associated with the casing to form a unitary structure, said cover-member also forming a wall of. the mufflerv with integral muiiler bafiie plates thereon.

6. In an apparatus of the class described, the combination of a casing, a turbine wheel mounted: therein upon a: shaft, and a relatively flat mufliing chamber spaced from said Wheel and lying. in a general plane sul tour of the face of said Wheel but spaced stantially parallel therewith, said mufiiing therefrom and forming a cover plate for chamber being provided With a central inthe turbine casing, said Wall being formed take opening also providing clearance for with a central intake opening also pr0vid 5 said shaft. 1 ing clearance for said shaft.

7. In an apparatus of the'class described, Signed at Depew, in the county of Erie, the combination of acasing, a turbine wheel and State of New York, this 14th day of mounted therein upon a shaft, and a rela- Feb. A. D. 1922. tively fiat mufiling chamber having a side WVILLIAM F. BOUCHE. 10 wall conforming substantially to the con ELI J. BLAKE. 

